From db97bc7f9997fef41b24c91f61c2f776d32d7ce3 Mon Sep 17 00:00:00 2001 From: Ananth N Mavinakayanahalli Date: Thu, 27 May 2010 19:19:20 +0000 Subject: [PATCH] powerpc/kprobes: Remove resume_execution() in kprobes emulate_step() in kprobe_handler() would've already determined if the probed instruction can be emulated. We single-step in hardware only if the instruction couldn't be emulated. resume_execution() therefore is superfluous -- all we need is to fix up the instruction pointer after single-stepping. Thanks to Paul Mackerras for catching this. Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/kprobes.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index c533525ca56a..bc47352deb1f 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -378,17 +378,6 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, * single-stepped a copy of the instruction. The address of this * copy is p->ainsn.insn. */ -static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) -{ - int ret; - unsigned int insn = *p->ainsn.insn; - - regs->nip = (unsigned long)p->addr; - ret = emulate_step(regs, insn); - if (ret == 0) - regs->nip = (unsigned long)p->addr + 4; -} - static int __kprobes post_kprobe_handler(struct pt_regs *regs) { struct kprobe *cur = kprobe_running(); @@ -406,7 +395,8 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs) cur->post_handler(cur, regs, 0); } - resume_execution(cur, regs); + /* Adjust nip to after the single-stepped instruction */ + regs->nip = (unsigned long)cur->addr + 4; regs->msr |= kcb->kprobe_saved_msr; /*Restore back the original saved kprobes variables and continue. */ -- 2.34.1